Radio transmission device and radio transmission method

Abstract

A power calculation section ( 105 ) calculates the power of a transmit signal that has passed through transmit frame generation sections ( 101 a through 101 c ), modulation sections ( 102 a through 102 c ), spreading sections ( 103 a through 103 c ), and a multiplexing section ( 104 ). A burst signal detection section ( 106 ) detects a burst signal from this power. Again calculation section ( 107 ) outputs fixed gain when a burst signal is detected. An attenuation amount calculation section ( 108 ) calculates an attenuation amount based on the gain calculated by the gain calculation section ( 107 ). The transmit signal is subjected to multiplication by the aforementioned gain in a gain multiplication section ( 109 ), predetermined radio processing in a transmitting radio section ( 110 ) and attenuation processing in accordance with the aforementioned attenuation amount in an attenuation section ( 111 ), and is transmitted from an antenna ( 112 ). By this means, it is possible to suppress excessive gain switching operations, and suppress modulation precision degradation and adjacent channel leakage power ratio degradation.

1 . A radio transmitting apparatus comprising: 
 an amplification section that amplifies power of a transmitting digital signal using predetermined amplification gain;    a conversion section that converts a post-amplification digital signal to an analog signal;    an attenuation section that attenuates power of an analog signal obtained by said conversion section to a power level of pre-amplification said digital signal; and    a determination section that determines whether or not pre-amplification said digital signal power is in a fluctuating state;    wherein said amplification section, when said determination section determines that said digital signal power is in a fluctuating state amplifies said digital signal power using fixed amplification gain, and when said determination section determines that said digital signal power is not in a fluctuating state amplifies said digital signal power using amplification gain that is in accordance with pre-amplification said digital signal power.    
     
     
         2 . The radio transmitting apparatus according to  claim 1 , wherein said determination section: 
 further comprises a counting section that counts a number of fluctuations of pre-amplification said digital signal power in a predetermined period; and    when a counted number of fluctuations is greater than or equal to a preset threshold value, determines that said digital signal power is in a fluctuating state.    
     
     
         3 . The radio transmitting apparatus according to  claim 1 , wherein said determination section determines whether or not pre-amplification said digital signal power is in a fluctuating state based on information relating to a setting of power contained in said digital signal.  
     
     
         4 . The radio transmitting apparatus according to  claim 1 , wherein said determination section does not determine whether or not pre-amplification said digital signal power is in a fluctuating state when it is reported beforehand that there is no fluctuation in pre-amplification said digital signal power.  
     
     
         5 . The radio transmitting apparatus according to  claim 1 , wherein said amplification section: 
 further comprises:    a calculation section that calculates amplification gain that is in accordance with pre-amplification said digital signal power each time pre-amplification said digital signal power is measured; and    a detection section that detects a minimum value of amplification gain calculated by said calculation section in a period in which it is determined whether or not pre-amplification said digital signal power is in a fluctuating state;    and amplifies said digital signal power using an amplification gain minimum value detected by said detection section.    
     
     
         6 . A base station apparatus provided with the radio transmitting apparatus according to  claim 1 .  
     
     
         7 . A radio transmitting method comprising: 
 an amplifying step of amplifying power of a transmitting digital signal using predetermined amplification gain;    a converting step of converting a post-amplification digital signal to an analog signal;    an attenuating step of attenuating power of an analog signal obtained by said converting step to a power level of pre-amplification said digital signal; and    a determining step of determining whether or not pre-amplification said digital signal power is in a fluctuating state;    wherein said amplifying step, when it is determined in said determining step that said digital signal power is in a fluctuating state amplifies said digital signal power using fixed amplification gain, and when it is determined in said determining step that said digital signal power is not in a fluctuating state amplifies said digital signal power using amplification gain that is in accordance with pre-amplification said digital signal power.    
     
     
         8 . A radio transmitting program that causes a computer to execute: 
 an amplifying step of amplifying power of a transmitting digital signal using predetermined amplification gain;    a converting step of converting a post-amplification digital signal to an analog signal;    an attenuating step of attenuating power of an analog signal obtained by said converting step to a power level of pre-amplification said digital signal; and    a determining step of determining whether or not pre-amplification said digital signal power is in a fluctuating state;    wherein said amplifying step, when it is determined in said determining step that said digital signal power is in a fluctuating state amplifies said digital signal power using fixed amplification gain, and when it is determined in said determining step that said digital signal power is not in a fluctuating state amplifies said digital signal power using amplification gain that is in accordance with pre-amplification said digital signal power.